Devices

• LINUX, like most operating systems, interacts with hardware devices via modularized software components called device drivers.
• A device driver hides the peculiarities of a hardware device's communication protocols from the operating system and allows the system to interact with the device through a standardized interface.
• Under Linux, device drivers are part of the kernel and may be either linked statically into the kernel or loaded on demand as kernel modules.
• Device drivers run as part of the kernel and aren't directly accessible to user processes. However, Linux provides a mechanism by which processes can communicate with a device driver -and through it with a hardware device- via file-like objects.
• These objects appear in the file system, and programs can open them, read from them, and write to them practically as if they were normal files.